1 Corinthians 15:32 mentions Paul's struggles with 'beasts at Ephesus' — the same location where he now chooses to stay until Pentecost.

Acts 18:19 shows Paul's initial arrival in Ephesus, the city where he later decides to remain until Pentecost.

Acts 20:16 records Paul's haste to reach Jerusalem by Pentecost, directly following his earlier plan to stay in Ephesus until that feast.

Acts 2:1 records the first Christian Pentecost when the Spirit came — the same festival Paul plans to observe in Ephesus.

Exodus 23:16 institutes the Feast of Harvest (Pentecost) — the feast Paul plans to remain in Ephesus until, grounding his timeline in OT calendar.

Leviticus 23:15-21 gives the detailed law for the Feast of Weeks (Pentecost) — the same feast Paul intends to stay in Ephesus until.

Deuteronomy 16:9 defines Pentecost as the Feast of Weeks, the Jewish harvest festival Paul waits for in Ephesus.